In a full operation mode, a low-rate radio communication module requires communication with a host module that controls the operation and data flow between the host module and the low-rate radio communication module. A host interface is usually implemented as a serial interface, such as a serial peripheral interface (SPI), a universal asynchronous receiver/transmitter (UART), or other similar interface. However, in some cases, communication modules can also operate without any control from a host module. In such cases, the data flow and/or operation mode is limited in some extent in comparison with a full operation mode. For example, data transmitted by a communication module might be constant so no data flow from a host module to a communication module is needed. Also, the behavior of a communication module may be constant which makes the existence of a controlling host module unnecessary. However, for initialization, operation control, and communication control, a host module has always been required.
In some cases, a default operation requires the existence of a host module that can offer complete control of data flow. On the other hand, the existence of a complete host module is not necessary if the application or the use does not necessitate it. In some cases, a very low amount of varying data is transferred in one packet and a duty cycle may be very low as well. At a minimum, payload information, such as a sensor value, might be only one bit or a byte, and in some applications, a packet frame containing an identification (ID) of a device indicating the existence of a device inside of a communication range is sufficient. As such, reduced host functionality/implementation is appropriate although the lower layers in the full extent are required.
Today, a host interface, such as an upper layer host interface (ULIF), of a communication module, such as a Bluetooth Low End Extension (BT-LEE) module, does not support different modes of operation. A host module and its active control exist for a default ULIF mode. However, implementations that target to extremely low power and simple applications requiring less power consumption of a host module are lacking. BT-LEE technology allows small devices to connect to other devices, such as mobile terminals, without the power and cost burden of traditional Bluetooth technology. Typical small devices include sensors, such as temperature sensors, toys, wireless pens, headsets, and other remote user interface peripherals. Further information regarding BT-LEE technology is described in Mauri Honkanen et al., “Low End Extension for Bluetooth,” IEEE Radio and Wireless Conference RAWCON 2004, Atlanta, Ga., September, 2004, pages 19-22.
Conventionally, devices with a short-range radio connectivity capability are implemented so that a host layer or unit, e.g. a micro-controller, controls the Medium Access Control (MAC) layer of a wireless communication module. FIG. 1 illustrates a conventional communication module 101. For example, when utilizing Bluetooth technology, interface 103 between a host layer or unit 105 and the MAC layer 107 is referred to as a Host Controller Interface (HCI). When utilizing BT-LEE technology, interface 103 is referred to as an Upper Layer Interface (ULIF). In relatively simple applications, a host layer 105 is not mandatory from the perspective of communication. As such, the functionality of host layer 105 can be significantly cut down. Additionally, the limited power resources of small devices necessitate that power consumption be minimized and pressure to minimize manufacturing costs drive manufacturers to develop simpler implementations. Therefore, it would be advantageous to minimize the requirements for a host layer.
Today, a BT-LEE communication module implementation does not support configuration of registers 109 or the use of memory space 111 remotely over an air interface. A full host implementation and its active control exist if registers 109 of the communication module 101 were configured. Implementations targeting extremely low power and simple applications do not require large power consumption by a full host module and therefore access to registers 109 and memory space 111 over an air interface would be advantageous.